Due to advances in breast cancer diagnosis and treatment, there has been a dramatic increase in the breast cancer survivor population. Chronic pain is a major clinical problem in this population, affecting 25 - 60% of survivors. Striking racial/ethnic health disparities are well established: African-American breast cancer survivors experience a disproportionate burden of pain compared to non-Hispanic Whites. The long-term goal of this project is to identify and describe racial group differences in the pathophysiological mechanisms and psychosocial factors contributing to pain in breast cancer survivors, and to use this knowledge (a) to determine unique variables which are of greatest importance and utility for determining which patients are at risk for developing persistent pain and (b) to develop mechanism-based effective individualized interventions for pain relief and pain prevention in racially diverse breast cancer survivor populations. We hypothesize that racial group differences in pain and pain-related disability in breast cancer survivors will be mediated by differences in pain processing mechanisms, modulated by autonomic, psychosocial, and inflammatory parameters. To determine the effect of race on pain in women treated for breast cancer we propose a longitudinal prospective study of African-American and non-Hispanic White women diagnosed with stage 1 and stage 2 breast cancer. Aim 1 will assess the prevalence, severity and timing of occurrence of pain in African-American and non- Hispanic White breast cancer survivors. Aim 2 will characterize racial group differences in experimental pain sensitivity and pain modulatory parameters longitudinally in African-American and non-Hispanic White breast cancer survivors using psychophysical measures. Aim 3 will determine the influence of race on the association between autonomic function and pain in African-American and non-Hispanic White breast cancer survivors. Aim 4 will assess the effect of race on the association between psychosocial processes and pain in African- American and non-Hispanic White breast cancer survivors. Aim 5 will assess the relationships between cytokines and pain in African-American and non-Hispanic White women treated for breast cancer. The results of these studies are expected to have a major impact on racial pain disparities in breast cancer survivors: (1) identification of standardized methods to assess racially diverse breast cancer survivors at-risk for chronic pain will allow clinicians and researchers to identify patients at-risk and to target those patients for early and tailored interventions; (2) identification of pathophysiological mechanisms contributing to racial pain disparities will allow to define important new targets for therapy and intervention to reduce and eliminate pain disparities in breast cancer survivors; (3) these studies will provide a key database to design and justify future clinical trials for the prevention and treatment of pain in racially diverse breast cancer survivors; and (4) in a larger context, the results of these studies will not only benefit African-American and non-Hispanic White women with breast cancer, but will have a significant impact on racial pain disparities in all cancer survivors.